Outcomes of Orca-Q in the Haplo SCT Setting for Hematologic Malignancies

Samer A. Srour, MD, MS, of The University of Texas MD Anderson Cancer Center, in Houston, Texas, discusses some of the takeaways from the dose-expansion phase of an ongoing phase 1 trial (NCT03802695) evaluating Orca-Q in the haploidentical stem cell transplant (haplo SCT) setting for patients with high-risk hematologic malignancies.

Orca-Q had acceptable safety with myeloablative conditioning (MAC) with only tacrolimus monotherapy. There was a low incidence of acute graft-vs-host disease, only 8% (95% CI, 2%-27%) of patients had grade 2 or higher aGVHD, and 5% (95% CI, 0%-25%) of patients had grade 3 or higher aGVHD.

Though the follow-up was relatively short, findings showed that at a median of 211 days (range, 32-1125) and with 16 of the 23 patients past the 3-month mark, there was not any moderate-to-severe chronic GVHD (cGVHD) seen and only 1 patient (6%) developed mild cGVHD.

At 1 year, the GVHD-and–relapse-free survival achieved with Orca-Q was 75%, which was noted to compare favorably with prior data reported in context of MAC, haplo SCT, and posttransplant cyclophosphamide.

Further data from the study was presented by Srour during the 2023 Transplantation & Cellular Therapy Meetings.

Transcription:

0:08 | One of the main outcomes in our study was graft-vs-host disease and the key always with it the transplant, generally speaking and more so in the haploidentical transplant, how can we decrease the graft-vs-host disease risk, and also the infections and the mortality without increasing the relapse. If we talk about the acute graft-vs-host disease, it was very low. Indeed, only 5% had severe acute GVHD, which is good for source disease in our patient population. That is encouraging compared with post transplant historical data.

1:12 | Then we looked at the chronic graft-vs-host disease. Immediate follow-up was around a little over 6 months in our patient cohort. We still need more follow-up, but at least it's a decent follow-up to start with. We didn't see any moderate or severe GVHD cases, which was also encouraging. Then, 1 of the most important outcomes to look at, regardless of everything I've said, is survival. Are patients alive? More important for me, are they alive with no complications? There's an interesting outcome we look at in the transplant. More and more these days are called graft-vs-host disease relapse-free survival, which means your patients are alive and without active disease without like they are in remission. This is a very good indicator or effective for a good quality-of-life if you can achieve a good number there.

1:51 | In our cohort, graft-vs-host disease relapse-free survival was 75%. This is extremely encouraging because historically, if you achieve 40%-50%, you'll be happy with that. In our cohort it was 75% and then the overall survival, which means any patients are alive at 1 year, also was the same at 75%. These are some of the main key outcomes from our study.